Understanding momentum, impulse and forces in soccer

These questions are for a post-grad degree in elite sports coaching - (biomechanics module)

Solution Preview

Q: Identify and explain propulsive and breaking forces in soccer?

Propulsive force is also known as thrust. Propulsive force is provided by the reaction to the soccer player from the ground. Since Force = mass x acceleration (Newton's 2nd Law of Motion), any acceleration of the body will be reflected in a reaction when at least one foot is on the ground.
Breaking force is applied when a soccer player decelerates and stops. This force too is provided by the ground. The breaking force is applied by the friction between the ground and the feet of the soccer player.

Q: Provide three examples where momentum influences soccer?
1 Heading a soccer ball: The distance of the header will be determined by the force provided by the player at impact. This force is due to the change in momentum (F=Change in momentum/ Time). Momentum is the product of (mass x velocity), so the total momentum of an athlete at any point is his mass times his velocity. The force applied by the player at impact will be determined by the speed of the run up, as well as by the number of ...